DARPA's proposed batteries would be smaller than these grains of salt (Photo: Mark Schellhase)

Article Summary

As development of micro- and nano-scale devices continues to advance, so does the need for an equally-tiny method of powering them. There’s not much point in developing a surveillance micro air vehicle the size of a housefly, for instance, if it requires a watch battery in order to fly. That’s why DARPA is funding a project to create really tiny batteries. Just how tiny are we talking, here? Well, they’re aiming for something smaller than a grain of salt.